title: Identification of factors for tuberculosis transmission via an integrated multidisciplinary approach.
abstract: It was reported previously that the major fraction of the recent decrease of tuberculosis incident cases in Arkansas had been due to a decrease in the reactivated infections. Preventing transmission of Mycobacterium tuberculosis is the key to a continued decline in tuberculosis cases. In this study, we integrated epidemiological data analysis and comparative genomics to identify host and microbial factors important to tuberculosis transmission. A significantly higher proportion of cases in large clusters (containing >10 cases) were non-Hispanic black, homeless, less than 65 years old, male sex, smear-positive sputum, excessive use of alcohol, and HIV sero-positive, compared to cases in small clusters (containing 2-5 cases) diagnosed within one year. However, being non-Hispanic black and homeless within the past year were the only two host characteristics that were identified as independent risk factors for being in large clusters. This finding suggests that social behavioral factors have a more important role in transmission of tuberculosis than does the infectiousness of the source. Comparing the genomic content of one of the large cluster strains to that of a non-clustered strain from the same community identified 25 genes that differed between the two strains, potentially contributing to the observed differences in transmission.
authors.affiliation: Department of Epidemiology, School of Public Health, University of Michigan, M5124 SPH II, 1415 Washington Heights, Ann Arbor, MI 48109-2029, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Talarico
authors.forename: Kashef
authors.initials: K
authors.lastname: Ijaz
authors.forename: Xinyu
authors.initials: X
authors.lastname: Zhang
authors.forename: Leonard N
authors.initials: LN
authors.lastname: Mukasa
authors.forename: Lixin
authors.initials: L
authors.lastname: Zhang
authors.forename: Carl F
authors.initials: CF
authors.lastname: Marrs
authors.forename: M Donald
authors.initials: MD
authors.lastname: Cave
authors.forename: Joseph H
authors.initials: JH
authors.lastname: Bates
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Yang
mesh_terms: D001741:Black or African American / Q000706:statistics & numerical data; D000368:Aged; D001131:Arkansas / Q000453:epidemiology; D016000:Cluster Analysis; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006679:HIV Seropositivity / Q000453:epidemiology; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006703:Ill-Housed Persons / Q000706:statistics & numerical data; D054884:Host-Pathogen Interactions; D006801:Humans; D033183:Interdisciplinary Communication; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D009169:Mycobacterium tuberculosis / Q000145:classification / Q000302:isolation & purification*; D012307:Risk Factors; D013183:Sputum / Q000382:microbiology; D014376:Tuberculosis / Q000453:epidemiology / Q000635:transmission*